A Brief History of Ajax
New technology quickly becomes so pervasive that it’s sometimes hard to remember what things were like before it. The latest example of this in miniature is the technique known as Ajax, which has become so widespread that it’s often thought that the technique has been around practically forever.
In some ways it has. During the first big stretch of browser innovation, Netscape added a feature known as LiveScript, which allowed people to put small scripts in web pages so that they could continue to do things after you’d downloaded them. One early example was the Netscape form system, which would tell you if you’d entered an invalid value for a field as soon as you entered it, instead of after you tried to submit the form to the server.
Shortly thereafter the bubble burst and web development crashed. Not, however, before Microsoft added a little-known function call named XMLHttpRequest to IE5. Mozilla quickly followed suit and, while nobody I know used it, the function stayed there, just waiting to be taken advantage of.
Google was apparently the first to realize what a sea change this was. With Gmail and Google Maps, they built applications that took advantage of this to provide a user interface that was much more like a web application. (The startup Oddpost, bought by Yahoo, actually predated this but their software was for-pay and so they didn’t receive as much attention.)
With Gmail, for example, the application is continually asking the server if there’s new email. If there is, then it live updates the page, it doesn’t make you download a new one. And Google Maps lets you drag a map around and, as you do so, automatically downloads the parts of it you want to look at inline, without making you wait for a whole new page to download.
And the rest is future history.
Both systems were relatively ill-supported by browsers in my experience. They were, after all, hacks. So while they both seemed extremely cool (KnowNow, in particular, had an awesome demo that allowed for a WYSIWYG SubEthaEdit-style live collaboration session in a browser), they never really took off.
You should follow me on twitterhere.
December 22, 2005